finitrd is a small initial ramdisk for Linux systems which have their root filesystem on a LVM volume. It is written in C and needs no other tools than a static linked lvm executable which is copied from /sbin from your running Linux system. Your kernel has to support procfs and sysfs. By default, the initial ramdisk contains an ext4 filesystem.
set timeout=10 set root=(vgcore1-lvroot1) insmod linux menuentry "Linux" { linux /boot/vmlinuz root=/dev/ram0 rootfstype=ext4 lvmroot=/dev/mapper/vgcore1-lvroot1 lvmrootfstype=ext4 lvmrootflags=data=journal,discard max_loop=64 devtmpfs.mount=0 initrd /boot/finitrd }